| 1. |
- Eriksson, Lars, et al.
(author)
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Modeling of a turbocharged SI engine
- 2002
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In: Annual Reviews in Control. - 1367-5788 .- 1872-9088. ; 26 I, s. 129-137
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Journal article (peer-reviewed)abstract
- Turbocharged SI engines are a major possibility in the current trend of down-sized engines with preserved drivability performance. Considering control and supervision it is favorable to have a mean value model to be used e.g. in observer design. Such models of turbo engines are similar to those of naturally aspirated engines, but there are some special characteristics, e.g. the interconnected gas flows, the intercooler, the difference in relative sizes between the gas volumes (compared to naturally aspirated engines), the turbo, and the waste gate. Here, a model is developed with a strategy to find a model for each engine component (air filter, compressor, after cooler (or intercooler), throttle, engine, turbine, waste gate, and a lumped model for the catalyst and exhaust) as they behave in an engine setting. When investigating agreement with measured data and sensitivity of possible model structures, a number of interesting issues are raised. The experiments and the model validation have been performed on a Saab 2.3 1 production engine.
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| 2. |
- Chen, Fei, et al.
(author)
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Cooperative control of heterogeneous multi-agent systems under spatiotemporal constraints
- 2024
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In: Annual Reviews in Control. - : Elsevier BV. - 1367-5788 .- 1872-9088. ; 57
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Research review (peer-reviewed)abstract
- A current trend in research on multi -agent control systems is to consider high-level task specifications that go beyond traditional control objectives and take into account the heterogeneity of each agent in the system, i.e., the different capabilities of the agents in terms of actuation, sensing, communication and computation. This article provides an overview of our work on the problem of control of heterogeneous multi -agent systems under both spatial and temporal constraints as well as our perspective on the challenges and open problems associated with the consideration of such spatiotemporal constraints. Initially, we review a set of control strategies introduced by the authors addressing the satisfaction of cooperative tasks such as formation control as well as individual objectives such as reference tracking. The satisfaction of those objectives is ensured using prescribed performance control. Building upon these approaches we then review recent results on control under high-level spatiotemporal objectives expressed in Signal Temporal Logic, a formal language that allows to express complex spatial tasks that must be satisfied within pre -defined deadlines. Theoretical results considering multi -agent systems with various capabilities under spatiotemporal constraints are presented.
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| 3. |
- Como, Giacomo
(author)
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On resilient control of dynamical flow networks
- 2017
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In: Annual Reviews in Control. - : Elsevier BV. - 1367-5788. ; 43, s. 80-90
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Journal article (peer-reviewed)abstract
- Resilience has become a key aspect in the design of contemporary infrastructure networks. This comes as a result of ever-increasing loads, limited physical capacity, and fast-growing levels of interconnectedness and complexity due to the recent technological advancements. The problem has motivated a considerable amount of research within the last few years, particularly focused on the dynamical aspects of network flows, complementing more classical static network flow optimization approaches.In this tutorial paper, a class of single-commodity first-order models of dynamical flow networks is considered. A few results recently appeared in the literature and dealing with stability and robustness of dynamical flow networks are gathered and originally presented in a unified framework. In particular, (differential) stability properties of monotone dynamical flow networks are treated in some detail, and the notion of margin of resilience is introduced as a quantitative measure of their robustness. While emphasizing methodological aspects -including structural properties, such as monotonicity, that enable tractability and scalability- over the specific applications, connections to well-established road traffic flow models are made.
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| 4. |
- Dencker, Kerstin, 1972-, et al.
(author)
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Proactive Assembly Systems – realizing the potential of human collaboration with automation
- 2009
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In: Annual Reviews in Control. - : Elsevier. - 1367-5788 .- 1872-9088. ; 33:2, s. 230-237
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Research review (peer-reviewed)abstract
- Manufacturing competitiveness frequently relies on company ability to rapidly reconfigure their assembly systems. This paper introduces assembly system proactivity, a concept based on interrelated levels of automation, human competence, and information handling. Increased and structured human involvement contributes to increased system ability to proactively address predicted and unpredicted events. Correct involvement of human operators will utilize the combined potential of human and technical capabilities, providing cost-efficient assembly system solutions. The ProAct project is developing proactive assembly system models and evaluates proactive, feature-based solutions. Focus is on realising the potential of cost-efficient and semi-automated systems with relevant human involvement, i.e. highly skilled operators who add flexibility and functionality.
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| 5. |
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| 6. |
- Dibaji, Seyed Mehran, et al.
(author)
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A systems and control perspective of CPS security
- 2019
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In: Annual Reviews in Control. - : PERGAMON-ELSEVIER SCIENCE LTD. - 1367-5788 .- 1872-9088. ; 47, s. 394-411
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Research review (peer-reviewed)abstract
- The comprehensive integration of instrumentation, communication, and control into physical systems has led to the study of Cyber-Physical Systems (CPSs), a field that has recently garnered increased attention. A key concern that is ubiquitous in CPS is a need to ensure security in the face of cyber attacks. In this paper, we carry out a survey of systems and control methods that have been proposed for the security of CPS. We classify these methods into three categories based on the type of defense proposed against the cyberattacks: prevention, resilience, and detection & isolation. A unified threat assessment metric is proposed in order to evaluate how CPS security is achieved in each of these three cases. Also surveyed are the risk assessment tools and the effect of network topology on CPS security. Furthermore, an emphasis has been placed on power and transportation applications in the overall survey.
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| 7. |
- Dimirovski, Georgi M, et al.
(author)
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Control system approaches for sustainable development and instability management in the globalization age
- 2006
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In: Annual Reviews in Control. - : Elsevier BV. - 1367-5788. ; 30:1, s. 103-115
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Journal article (peer-reviewed)abstract
- The civilization of mankind in the globalization age depends heavily on advanced information technologies emerging from automation and decision expertise and their respective scientific disciplines. The broad area of social systems, being essentially human centred systems, is a cross-, inter- and multi-disciplinary challenge to the control community. Social systems of contemporary civilization are reviewed from the systems science viewpoint and on the grounds of recent developments in control science and technology. Recent developments have emphasised the social responsibility of the control community during the on-going globalization and changes from the Cold-War bipolar world to a unipolar one, on the way to mankind's multi-polar world of the future. © 2006 Elsevier Ltd. All rights reserved.
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| 8. |
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| 9. |
- Grubbström, Robert W., et al.
(author)
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Optimal lotsizing within MRP Theory
- 2010
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In: Annual Reviews in Control. - : Elsevier. - 1367-5788 .- 1872-9088. ; 34:1, s. 89-100
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Journal article (peer-reviewed)abstract
- MRP Theory combines the use of Input-Output Analysis and Laplace transforms, enabling the development of a theoretical background for multi-level, multi-stage production-inventory systems together with their economic evaluation, in particular applying the Net Present Value principle (NPV) In this paper we concentrate our attention on the question of optimal lotsizing decisions within the MRP Theory framework. MRP Theory has mainly dealt with assembly structures by which items produced downstream (on a higher level in the product structure) contain one or more sub-items on lower levels, but at each stage, the assembly activity produces only one type of output. This enables the input matrix, after enumerating all items suitably, to be organised as a triangular matrix, with non-zero elements only appearing below its main diagonal. The introduction of a diagonal lead time matrix capturing the advanced timing when required Inputs are needed, enables compact expressions to be obtained, explaining the development of key variables such as available inventory and backlogs in the frequency domain. Central in this theory is the generalised input matrix showing when and how much the internal (dependent) demand amounts to for any production plan. Previously has been demonstrated that in a one-product case, inner-corner conditions for an optimum production plan in continuous time reduce the number of possible replenishment times to a finite set of given points at which either a replenishment is made, or not. The dynamic lotsizing problem is thus turned into choosing from a set of zero-one decisions with 2(m-1) alternatives, of which one (or possibly several equivalent) solution(s) must be optimal, where m is the number of requirement (demand) events. Given these points in time and the corresponding staircase function describing cumulative demand, the optimal plan may be obtained, for instance by employing the Triple Algorithm of dynamic lotsizing. This applies either an Average Cost approach, or the Net Present Value principle is applied In this paper, we extend this analysis to a general multi-item system of the assembly type. Among other issues, it is shown how the number of internal demand events depends on product structure and number of external demand events. Also the inner-corner condition is proven still to be valid in this somewhat more complex situation, when demand for lower-level items no longer is given from the outset, but instead depends on decisions concerning production of items on higher levels in the product structure. A simple dynamic program procedure is provided offering a solution to maximising the NPV for any general assembly system. To solve for the optimal production plan, the Triple Algorithm may be applied to each stage.
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| 10. |
- Gustafsson, Fredrik
(author)
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Statistical Signal Processing Approaches to Fault Detection
- 2007
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In: Annual Reviews in Control. - : Elsevier. - 1367-5788 .- 1872-9088. ; 31:1, s. 41-54
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Journal article (peer-reviewed)abstract
- The parity space approach to fault detection and isolation (FDI) has been developed during the last 20 years, and the focus here is to describe its application to stochastic systems. A mixed model with both stochastic inputs and deterministic disturbances and faults is formulated over a sliding window. Algorithms for detecting and isolating faults on-line and analyzing the probability for correct and incorrect decisions off-line are provided. A major part of the paper is devoted to discussing properties of this model-based approach and generalizations to cases of incomplete model knowledge, and non-linear non-Gaussian models. For this purpose, a simulation example is used throughout the paper for numerical illustrations, and real-life applications for motivations. The final section discusses the reverse problem: fault detection approaches to statistical signal processing. It is motivated by three applications that a simple CUSUM detector in feedback loop with an adaptive filter can mitigate the inherent trade-off between estimation accuracy and tracking speed in linear filters.
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